When I see these letters, I think, "Oh, it's a c with a little hat," but this is not how a Bosnian speaker thinks. To him, č and c are no more alike than d and b are to an English speaker. There are similarities in how you write them, but the letters are completely different. (As I learn time after time when I can't find words in the dictionary because I'm looking under the wrong letter!)
Isaac’s school is named for a poet whose name requires many diacritical marks: Musa Ćazim Ćatić. When Isaac got his Cossack-like school jacket,
we were tickled to see that even the monogramming doesn't ignore those marks.
Although I have problems with the concept that a letter with a diacritcal mark is not the same as a letter without a diacritical mark, Eleanor has it down pat. Recently I was trying to write a word she had learned in kindergarten, and I was having problems with the spelling. “Is that with a z?” I asked her.
She rolled her eyes. “Of course it’s not. ‘Z’ is like this z-z-z-z-z. Listen to this. ‘Zh-zh-zh-zh-zh.’ You write it like this.” She took the pencil from my hand and wrote ž.
To me, a z with a little hat on it. To Bosnians, and to my daughter, not a z at all.